2 * Copyright (c) 1999 Michael Smith
4 * Copyright (c) 1999 Poul-Henning Kamp
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * $FreeBSD: src/sys/kern/vfs_conf.c,v 1.49.2.5 2003/01/07 11:56:53 joerg Exp $
32 * Locate and mount the root filesystem.
34 * The root filesystem is detailed in the kernel environment variable
35 * vfs.root.mountfrom, which is expected to be in the general format
38 * vfsname := the name of a VFS known to the kernel and capable
39 * of being mounted as root
40 * path := disk device name or other data used by the filesystem
41 * to locate its physical store
45 #include "opt_rootdevname.h"
47 #include <sys/param.h>
48 #include <sys/kernel.h>
49 #include <sys/systm.h>
51 #include <sys/vnode.h>
52 #include <sys/mount.h>
53 #include <sys/malloc.h>
54 #include <sys/reboot.h>
55 #include <sys/diskslice.h>
58 #include <sys/device.h>
60 #include <sys/namecache.h>
61 #include <sys/paths.h>
62 #include <sys/thread2.h>
63 #include <sys/nlookup.h>
64 #include <sys/devfs.h>
65 #include <sys/sysctl.h>
72 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
74 #define ROOTNAME "root_device"
76 struct vnode *rootvnode;
77 struct nchandle rootnch;
80 * The root specifiers we will try if RB_CDROM is specified. Note that
81 * with DEVFS we do not use the compatibility slice's whole-disk 'c'
82 * partition. Instead we just use the whole disk, e.g. cd0 or cd0s0.
84 static char *cdrom_rootdevnames[] = {
85 "cd9660:cd0", /* SCSI (including AHCI and SILI) */
86 "cd9660:acd0", /* NATA */
87 "cd9660:cd1", /* SCSI (including AHCI and SILI) */
88 "cd9660:acd1", /* NATA */
89 "cd9660:cd8", /* USB */
90 "cd9660:cd9", /* USB */
94 int vfs_mountroot_devfs(void);
95 static void vfs_mountroot(void *junk);
96 static int vfs_mountroot_try(const char *mountfrom);
97 static int vfs_mountroot_ask(void);
98 static int getline(char *cp, int limit);
100 /* legacy find-root code */
101 char *rootdevnames[2] = {NULL, NULL};
102 static int setrootbyname(char *name);
104 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL);
106 static int wakedelay = 2; /* delay before mounting root in seconds */
107 TUNABLE_INT("vfs.root.wakedelay", &wakedelay);
110 * Find and mount the root filesystem
113 vfs_mountroot(void *junk)
115 cdev_t save_rootdev = rootdev;
120 * Make sure all disk devices created so far have also been probed,
121 * and also make sure that the newly created device nodes for
122 * probed disks are ready, too.
124 * Messages can fly around here so get good synchronization
127 * XXX - Delay some more (default: 2s) to help drivers which pickup
128 * devices asynchronously and are not caught by CAM's initial
132 tsleep(&dummy, 0, "syncer", hz * wakedelay);
136 * The root filesystem information is compiled in, and we are
137 * booted with instructions to use it.
140 if ((boothowto & RB_DFLTROOT) &&
141 !vfs_mountroot_try(ROOTDEVNAME))
145 * We are booted with instructions to prompt for the root filesystem,
146 * or to use the compiled-in default when it doesn't exist.
148 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) {
149 if (!vfs_mountroot_ask())
154 * We've been given the generic "use CDROM as root" flag. This is
155 * necessary because one media may be used in many different
156 * devices, so we need to search for them.
158 if (boothowto & RB_CDROM) {
159 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
160 if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
166 * Try to use the value read by the loader from /etc/fstab, or
167 * supplied via some other means. This is the preferred
170 if (!vfs_mountroot_try(kgetenv("vfs.root.mountfrom")))
174 * If a vfs set rootdev, try it (XXX VINUM HACK!)
176 if (save_rootdev != NULL) {
177 rootdev = save_rootdev;
178 if (!vfs_mountroot_try(""))
183 * Try values that may have been computed by the machine-dependant
186 if (rootdevnames[0] && !vfs_mountroot_try(rootdevnames[0]))
188 if (rootdevnames[1] && !vfs_mountroot_try(rootdevnames[1]))
192 * If we have a compiled-in default, and haven't already tried it, try
196 if (!(boothowto & RB_DFLTROOT))
197 if (!vfs_mountroot_try(ROOTDEVNAME))
202 * Everything so far has failed, prompt on the console if we haven't
203 * already tried that.
205 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask())
207 panic("Root mount failed, startup aborted.");
212 vfs_mountroot_devfs(void)
216 struct nlookupdata nd;
218 struct vfsconf *vfsp;
220 struct ucred *cred = proc0.p_ucred;
221 const char *devfs_path, *init_chroot;
222 char *dev_malloced = NULL;
224 if ((init_chroot = kgetenv("init_chroot")) != NULL) {
227 l = strlen(init_chroot) + sizeof("/dev");
228 dev_malloced = kmalloc(l, M_MOUNT, M_WAITOK);
229 ksnprintf(dev_malloced, l, "%s/dev", init_chroot);
230 devfs_path = dev_malloced;
235 * Lookup the requested path and extract the nch and vnode.
237 error = nlookup_init_raw(&nd,
238 devfs_path, UIO_SYSSPACE, NLC_FOLLOW,
242 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup_init is ok...\n");
243 if ((error = nlookup(&nd)) == 0) {
244 devfs_debug(DEVFS_DEBUG_DEBUG, "vfs_mountroot_devfs: nlookup is ok...\n");
245 if (nd.nl_nch.ncp->nc_vp == NULL) {
246 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup: simply not found\n");
251 if (dev_malloced != NULL)
252 kfree(dev_malloced, M_MOUNT), dev_malloced = NULL;
256 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: nlookup failed, error: %d\n", error);
261 * Extract the locked+refd ncp and cleanup the nd structure
264 cache_zero(&nd.nl_nch);
268 * now we have the locked ref'd nch and unreferenced vnode.
271 if ((error = vget(vp, LK_EXCLUSIVE)) != 0) {
273 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vget failed\n");
278 if ((error = vinvalbuf(vp, V_SAVE, 0, 0)) != 0) {
281 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vinvalbuf failed\n");
284 if (vp->v_type != VDIR) {
287 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vp is not VDIR\n");
291 vfsp = vfsconf_find_by_name("devfs");
294 * Allocate and initialize the filesystem.
296 mp = kmalloc(sizeof(struct mount), M_MOUNT, M_ZERO|M_WAITOK);
298 vfs_busy(mp, LK_NOWAIT);
299 mp->mnt_op = vfsp->vfc_vfsops;
301 vfsp->vfc_refcount++;
302 mp->mnt_stat.f_type = vfsp->vfc_typenum;
303 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
304 strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
305 mp->mnt_stat.f_owner = cred->cr_uid;
309 * Mount the filesystem.
311 error = VFS_MOUNT(mp, "/dev", NULL, cred);
313 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
316 * Put the new filesystem on the mount list after root. The mount
317 * point gets its own mnt_ncmountpt (unless the VFS already set one
318 * up) which represents the root of the mount. The lookup code
319 * detects the mount point going forward and checks the root of
320 * the mount going backwards.
322 * It is not necessary to invalidate or purge the vnode underneath
323 * because elements under the mount will be given their own glue
327 if (mp->mnt_ncmountpt.ncp == NULL) {
329 * allocate, then unlock, but leave the ref intact
331 cache_allocroot(&mp->mnt_ncmountpt, mp, NULL);
332 cache_unlock(&mp->mnt_ncmountpt);
334 mp->mnt_ncmounton = nch; /* inherits ref */
335 nch.ncp->nc_flag |= NCF_ISMOUNTPT;
337 /* XXX get the root of the fs and cache_setvp(mnt_ncmountpt...) */
338 mountlist_insert(mp, MNTINS_LAST);
340 //checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
341 error = vfs_allocate_syncvnode(mp);
343 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: vfs_allocate_syncvnode failed\n");
346 error = VFS_START(mp, 0);
349 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
350 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
351 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
352 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
353 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
354 mp->mnt_vfc->vfc_refcount--;
359 devfs_debug(DEVFS_DEBUG_SHOW, "vfs_mountroot_devfs: mount failed\n");
362 devfs_debug(DEVFS_DEBUG_DEBUG, "rootmount_devfs done with error: %d\n", error);
368 * Mount (mountfrom) as the root filesystem.
371 vfs_mountroot_try(const char *mountfrom)
374 char *vfsname, *devname;
387 if (mountfrom == NULL)
388 return(error); /* don't complain */
391 kprintf("Mounting root from %s\n", mountfrom);
395 /* parse vfs name and devname */
396 vfsname = kmalloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
397 devname = kmalloc(MNAMELEN, M_MOUNT, M_WAITOK);
398 mf = kmalloc(MFSNAMELEN+MNAMELEN, M_MOUNT, M_WAITOK);
400 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
401 bzero(vfsname, MFSNAMELEN);
402 bzero(devname, MNAMELEN);
403 bzero(mf, MFSNAMELEN+MNAMELEN);
404 strncpy(mf, cp, MFSNAMELEN+MNAMELEN);
406 vfsname[0] = devname[0] = 0;
407 ksprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
408 if (ksscanf(mf, patt, vfsname, devname) < 1)
411 /* allocate a root mount */
412 error = vfs_rootmountalloc(vfsname,
413 devname[0] != 0 ? devname : ROOTNAME, &mp);
415 kprintf("Can't allocate root mount for filesystem '%s': %d\n",
419 mp->mnt_flag |= MNT_ROOTFS;
421 /* do our best to set rootdev */
422 if ((strcmp(vfsname, "hammer") != 0) && (devname[0] != 0) &&
423 setrootbyname(devname))
424 kprintf("setrootbyname failed\n");
426 /* If the root device is a type "memory disk", mount RW */
427 if (rootdev != NULL && dev_is_good(rootdev) &&
428 (dev_dflags(rootdev) & D_MEMDISK)) {
429 mp->mnt_flag &= ~MNT_RDONLY;
432 error = VFS_MOUNT(mp, NULL, NULL, proc0.p_ucred);
443 kfree(vfsname, M_MOUNT);
445 kfree(devname, M_MOUNT);
449 /* register with list of mounted filesystems */
450 mountlist_insert(mp, MNTINS_FIRST);
452 /* sanity check system clock against root fs timestamp */
453 inittodr(mp->mnt_time);
455 /* Get the vnode for '/'. Set p->p_fd->fd_cdir to reference it. */
456 mp = mountlist_boot_getfirst();
457 if (VFS_ROOT(mp, &vp))
458 panic("cannot find root vnode");
459 if (mp->mnt_ncmountpt.ncp == NULL) {
460 cache_allocroot(&mp->mnt_ncmountpt, mp, vp);
461 cache_unlock(&mp->mnt_ncmountpt); /* leave ref intact */
464 p->p_fd->fd_cdir = vp;
465 vref(p->p_fd->fd_cdir);
466 p->p_fd->fd_rdir = vp;
467 vref(p->p_fd->fd_rdir);
468 vfs_cache_setroot(vp, cache_hold(&mp->mnt_ncmountpt));
469 vn_unlock(vp); /* leave ref intact */
470 cache_copy(&mp->mnt_ncmountpt, &p->p_fd->fd_ncdir);
471 cache_copy(&mp->mnt_ncmountpt, &p->p_fd->fd_nrdir);
474 if (mp->mnt_syncer == NULL) {
475 error = vfs_allocate_syncvnode(mp);
477 kprintf("Warning: no syncer vp for root!\n");
486 kprintf("Root mount failed: %d\n", error);
493 vfs_mountroot_ask_callback(char *name, cdev_t dev, bool is_alias,
496 if (!is_alias && dev_is_good(dev) && (dev_dflags(dev) & D_DISK))
497 kprintf(" \"%s\" ", name);
502 * Spin prompting on the console for a suitable root filesystem
505 vfs_mountroot_ask(void)
510 kprintf("\nManual root filesystem specification:\n");
511 kprintf(" <fstype>:<device> Specify root (e.g. ufs:da0s1a)\n");
512 kprintf(" ? List valid disk boot devices\n");
513 kprintf(" panic Just panic\n");
514 kprintf(" abort Abort manual input\n");
516 kprintf("\nmountroot> ");
518 if (getline(name, 128) < 0)
522 } else if (name[0] == '?') {
523 kprintf("Possibly valid devices for root FS:\n");
524 //enumerate all disk devices
525 devfs_scan_callback(vfs_mountroot_ask_callback, NULL);
528 } else if (strcmp(name, "panic") == 0) {
529 panic("panic from console");
530 } else if (strcmp(name, "abort") == 0) {
532 } else if (vfs_mountroot_try(name) == 0) {
541 getline(char *cp, int limit)
579 if (lp - cp >= limit - 1) {
591 * Convert a given name to the cdev_t of the disk-like device
595 kgetdiskbyname(const char *name)
600 * Get the base name of the device
602 if (strncmp(name, __SYS_PATH_DEV, sizeof(__SYS_PATH_DEV) - 1) == 0)
603 name += sizeof(__SYS_PATH_DEV) - 1;
608 rdev = devfs_find_device_by_name("%s", name);
610 kprintf("no disk named '%s'\n", name);
619 * Set rootdev to match (name), given that we expect it to
620 * refer to a disk-like device.
623 setrootbyname(char *name)
627 diskdev = kgetdiskbyname(name);
628 if (diskdev != NULL) {
632 /* set to NULL if kgetdiskbyname() fails so that if the first rootdev is
633 * found by fails to mount and the second one isn't found, mountroot_try
634 * doesn't try again with the first one
641 DB_SHOW_COMMAND(disk, db_getdiskbyname)
645 if (modif[0] == '\0') {
646 db_error("usage: show disk/devicename");
649 dev = kgetdiskbyname(modif);
651 db_printf("cdev_t = %p\n", dev);
653 db_printf("No disk device matched.\n");
658 vfs_sysctl_real_root(SYSCTL_HANDLER_ARGS)
664 real_root = kgetenv("vfs.root.realroot");
666 if (real_root == NULL)
669 len = strlen(real_root) + 1;
671 error = sysctl_handle_string(oidp, real_root, len, req);
676 SYSCTL_PROC(_vfs, OID_AUTO, real_root,
677 CTLTYPE_STRING | CTLFLAG_RD, 0, 0, vfs_sysctl_real_root,
678 "A", "Real root mount string");